Modelling Solar-like Oscillations in Boo
نویسندگان
چکیده
Kjeldsen et al. (1995, AJ in press) recently obtained strong evidence for solar-like oscillations in the G0 IV star Boo. Here we present evolution calculations for the star and compare them with the observed oscillation frequencies. Models can be found that are consistent with the star's luminosity and eeective temperature and with the large and small frequency separations. The calculations indicate that dipolar (l = 1) oscillations behaving like gravity modes in the interior of the star can be excited to observable amplitudes; the observations may show evidence for such modes. 1 1. INTRODUCTION The probable detection of solar-like oscillations in Boo (Kjeldsen et al. 1995) provides an important opportunity to test stellar evolution theory. Each mode in an oscillating star is characterized by a radial order n and an angular degree l, and the mode frequencies are sensitive to conditions in the stellar interior (see Brown & Gilliland 1994 for a recent review). The frequencies nl of low-degree modes satisfy the following asymptotic relation:
منابع مشابه
12 Boötis : a test bed for extra - mixing processes in stars 3
12 Boötis is a spectroscopic binary whose visual orbit has been resolved by interferometry. Though the physical parameters of the system have been determined with an excellent precision, the theoretical modelling of the components is still uncertain. We study the capability of solar-like oscillations to distinguish between calibrated models of the system obtained by including in the stellar mod...
متن کاملConfirmation of solar-like oscillations in eta Bootis
We obtained time-series spectroscopy of the G0 subgiant η Boo in an attempt to confirm the solar-like oscillations reported by Kjeldsen et al. (1995). We recorded 1843 spectra over six consecutive nights with the Nordic Optical Telescope, which we used to measure equivalent widths of strong temperature-sensitive lines. We also measured velocities from 1989 spectra obtained through an iodine ref...
متن کاملEvidence for Solar-like Oscillations in Arcturus (α Boo)
Abstract. Observations of the red giant Arcturus (α Boo) obtained with the star tracker on the Wide Field Infrared Explorer (WIRE) satellite during a baseline of 19 successive days in 2000 July-August are analysed. The power spectrum has a significant excess of power at low-frequencies. The highest peak is at ∼4.1 μHz, which is in agreement with the ground-based radial velocity and photometry s...
متن کاملMeasuring stellar oscillations using equivalent widths of absorption lines
Kjeldsen et al. (1995) have developed a new technique for measuring stellar oscillations and claimed a detection in the G subgiant η Boo. The technique involves monitoring temperature fluctuations in a star via their effect on the equivalent width of Balmer lines. In this paper we use synthetic stellar spectra to investigate the temperature dependence of the Balmer lines, Ca ii, Fe i, the Mg b ...
متن کاملas tr o - ph / 9 41 10 16 3 N ov 9 4 Solar - like oscillations in
We have observed evidence for p-mode oscillations in the G0 IV star Boo (V = 2:68). This represents the rst clear evidence of solar-like oscillations in a star other than the Sun. We used a new technique which measures uctuations in the temperature of the star via their eeect on the equivalent widths of the Balmer lines. The observations were obtained over six nights with the 2.5 m Nordic Optic...
متن کامل